Data centers are facilities used to house computer systems and related devices, such as power supplies, communications and storage systems, environmental controls (such as air conditioning and fire suppression) and various security devices. A number of techniques have been proposed or suggested for automatically navigating, mapping and/or monitoring data centers. For example, J. Lenchner et al., “Towards Data Center Self-Diagnosis Using a Mobile Robot,” ACM Intl Conf. on Autonomic Computing (ICAC '11) (2011), incorporated by reference herein, discloses a robot that serves as a physical autonomic element to automatically navigate, map and monitor data centers. The disclosed robot navigates a data center, mapping its layout and monitoring its temperature and other quantities of interest with little, if any, human assistance. In addition, U.S. patent application Ser. No. 13/348,846, filed Jan. 12, 2012 (now U.S. Pat. No. 9,606,542), entitled “Discovery and Monitoring of an Environment Using a Plurality of Robots,” incorporated by reference herein, discloses techniques for coordinating multiple mobile robots for exploring and monitoring a given environment or region.
Radio Frequency Identification (RFID) tags are often used in numerous industrial applications as a method for ready identification of a given asset. An asset is first tagged with a given RFID tag and the association is commonly stored in an asset database. Typically, active RFID tags broadcast their respective serial number on a periodic basis and a receiver then records the received serial number along with the signal strength of the received signal and the location at which the signal was received. While RFID tags have greatly improved the ability to readily track equipment, they suffer from a number of limitations, which if overcome, could further extend the utility and efficiency of systems that either automatically or semi-automatically track equipment. Localizing the assets to a desired granularity is often quite difficult due to, for example, multipath propagation of signals and directional interference.
A need therefore remains for improved techniques for localizing a source of a set of radio signals, such as radio signals received from an RFID tag at various locations.